Fluid valve means for mine roof supports



Sept. 2, 1969 F. TOWN FLUID VALVE MEANS FOR MINE ROOF SUPPORTS 16 Sheets-Sheet 1 Filed Nov. 30. 1966 Sept. 2, 1969 F. TOWN FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30. 1966 16 Sheets-Sheet 2 um q F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS 16 Sheets-Sheet Sept. 2, 1969 Filed Nov. 30, 1966 Sept. 2, 1969 F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 50. 1966 16 Sheets-Sheet 4 Sept. 2, 1969 F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30, 1966 16 Sheets-Sheet 5 iil l-i-i 60 F166 Sept. 2, 1969 F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS 4 Filed Nov. 30, 1966 16 Sheets-Sheet 6 I 1% D 42 1 1 I l v, 7 i I: L 2

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Sept. 2, 1969 F. TOWN FLUID VALVE MEANS FOR MINE ROOF SUPPORTS.

, Filed Nov. ISO, 1966 16 Sheets-Sheet '7 m Tmm hm 6mm F Du mm Sept. 2, 1969 F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30, 1966 16 Sheets-Sheet 8 Sept. 2, 1969 F. TOWN FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Tiled Nov. 30, 1966 16 Sheets-Sheet 9 Sept. 2, 1969 F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30. 1966 16 Sheets-Sheet 1O Sept. 2, 1969 F. TOWN 3,

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30.1966 16 Sheets-Sheet 11 Sept. 2, 1969 F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SU PPORTS Filed Nov. 30, 1966 16 Sheets-Sheet 12 Se t. 2, 1969 F. TOWN 3,464,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30, 1966 16 Sheets-Sheet 15 360 74 87 7 6 HG I5 r i '1 75 M k 4 N 366* .1: l.;.: T i 87 I z 3 Sept. 2, 1969 F. TOWN FLUID VALVE MEANS FOR MINE ROOF SUPPORTS 1 6 Sheets-Sheet 14 Filed Nov. 30, 1966 Sept. 2, 1969 F. TOWN 3,454,445

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30, 1966 16 Sheets-Sheet 15 Se t. 2, 1969 F. TOWN 3,

FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Filed Nov. 30, 1966 16 Sheets-Sheet 16 3,464,445 FLUID VALVE MEANS FOR MINE ROOF SUPPORTS Frank Town, Burton Joyce, England, assignor to W. E. & F. Dobson Limited Filed Nov. 30, 1966, Ser. No. 598,079 Int. Cl. F161; 11/18 US. Cl. 137-59618 10 Claims ABSTRACT OF THE DISCLOSURE Control valve means, for required sequential control of mine roof supports with hydraulic props and advancing cylinders and rams, wherein a basic control valve block has feed and return connections to one end of the props and controlling non-return valves, a remote control valve block is secured to the basic control valve block and has connections to the other end of the props and to the advancing cylinder and ram, said remote control valve block having passages communicating with the basic control valve block and a two-part slide valve operable -by fluid signals to control operation of the props and cylinder and ram, and there being inter-changeably connectable to the remote control valve block third valve blocks having a fluid operable valve, or a manually operable valve, or a solenoid operable valve.

This invention relates to improvements in fluid valve means for mine roof supports of the type which embody hydraulic mine roof cylinder and ramp props adapted for vertical extension and contraction and which are stepwise advanceable horizontally by extension and contraction of a horizontal hydraulic cylinder and ram.

In one known means of controlling the extensions and contractions of the prop vertically and of the advancing cylinder and ram horizontally a control valve block is provided with main fluid feed, return and service, valve controlled throughway passages, and with hand controlled disc valve devices in predetermined relationship to said passages by which communication can be effected alternatively between the main fluid feed or return and service passages.

It is also alternatively known to provide a hydraulic remote control arrangement whereby the control valves of a plurality or batch of supports are controllable advantageously from a remote position. In this arrangement the control has been eifeeted by means of a pilot or servo system additional to the main fluid supply. In a proposed improvement this pilot or servo system is dispensed with and instead solenoid operated valves are fitted to the control valves for controlling the main fluid in such manner so that the main fluid is electro hydraulically controlled to operate the control valve, there being also provided means ensuring that operation of the control valves does not cause any drop in the main fluid pressure.

It is further desirable to alternatively control each support by hand operation of a control valve on an adjacent support.

The above arrangements i.e. the hand control for controlling a support on which it is mounted, the hand control for control of a support adjacent to the support on which it is mounted, the batch support control, and the electro hydraulic control, have been such that only one, or at least only two, of the arrangements can be provided for any single control system.

An object of the invention is to provide control valve means of such improved construction that it is readily adaptable for control by any one of the four different arrangements at any required different times.

The invention provides control valve means comprising a basic control valve block formed with throughway main nited States Patent Patented Sept. 2, 1969 fluid feed, return, and service passages, and incorporating non-return valve means, a remote control valve block attached to the basic control valve block and having, main fluid feed, return, and service passages which register with those of the basic valve block, signal controllable valve means operable for alternatively opening the service passages to the feed and return passages, and signal and service passages extending from said valve means to an outer surface of the block, and a third valve block attached to the remote control valve block and having at least one passage registering with a passage in the remote control block. Conveniently the third valve block has passages registering with said signal and service passages, pilot signal and service passages adapted for pilot and direct connection to additional services, and valve means which are automatically operated relative to the latter passages for control of the various services. Alternatively the third valve block has only a passage registering with pulse signal passage in the remote valve block, and the valve means as a disc valve manually operated. Further alternatively the third valve block is of a solenoid operated control valve. Conveniently the valve means in the remote control block comprises a slide valve in two co-axial sections which are operable to change the relationship between the feed, return, and service passages by a pulse signal being directed by said signal passage to a location between the two slide sections. Conveniently also there are at least two service passages matching between the basic valve block and the remote valve block, one of the service passages being under control of one of said valve sections and the other being under control of the other valve section. One of the valve sections is conveniently of unitary form operable for opening and closing communication between the feed and one of the service passages, and the other section is of two-way valve form for controlling communication between the feed passage and the other service passage and between the two service passages and the return passage. The remote control block is conveniently fitted to the basic valve block and the third block is fitted to the remote control block in readily removable manner by screws.

In a particular application of the invention the services are hydraulic props in hydraulic mine roof supports and advancing cylinder and ram devices.

The foregoing and other features of the invention set out in the appended claim are incorporated in the specific embodiment hereinafter particularly described with reference to the accompanying drawings in which:

FIGURE 1 is a partly diagrammatic view showing a mine roof support and connections therefrom to a known form of a manually operable control valve shown enlarged.

FIGURE 2 is a plan view of the control valve.

FIGURE 3 is an end view of the control valve.

FIGURE 4 is a diagrammatic view of the support and part of the control valve in enlarged section.

FIGURE 5 is a front face view of part of the valve.

FIGURE 6 is a front face view of an added part of the valve.

FIGURE 7 is a plan view of the valve with the added part in section.

FIGURE 8 is a diagrammatic sectional view of the valve with the added part.

FIGURE 9 is a front view of the valve with a further added part.

FIGURE 10 is a plan view of FIGURE 9 with the further added part in section.

FIGURE 11 is a further sectional view of the added part.

FIGURE 12 is a still further sectional view of the added part.

FIGURE 13 is a diagrammatic illustration of the sup port connected to the valve with the added parts and part of an advancing cylinder and ram in enlarged section.

FIGURE 14 is a reproduction of part of FIGURE 13 at a different stage in operation of the valve.

FIGURE 15 is a reproduction of part of FIGURE 13 at a further stage in operation of the valve.

FIGURE 16 is a sectional view of part of FIGURE 13 at a still further stage in operation of the valve.

FIGURE 17 is a front view of the valve with said further part substituted by a manually operable valve.

FIGURE 18 is a sectional view of part of FIGURE 17.

FIGURE 19 is a further sectional view of FIGURE 17.

FIGURE 20 is a front view of the valve with a solenoid operated valve substituted for the manually controlled valve.

FIGURE 21 is a plan view of FIGURE 20.

FIGURE 22 is an end view of FIGURE 20.

Referring to FIGURE 1 a mine roof support of the kind hereinafter referred to is represented by three hydraulic props 13, 14, 15 on a common base and having a common roof bar and an advancing cylinder and ram whereof the cylinder 24 is carried by the support and the ram 25 is attached to a work face conveyor. For control of the props 13, 14, 15 and the advancing cylinder 24 and ram 25 there has been a manually operable control valve 1.

This control valve 1 has a fluid feed passage 4, FIG- URE 2, and a return passage which are connected in a hydraulic system. There are also services passages 7, 8, 9 connected by pipelines 10, 11, 12, FIGURE 1, to the lower cylinder ends of the three props, a service passage 19 connected by pipelines 20, 21 to the annuli of the props, and service passages P, P1 connected to opposite ends of the cylinder 24.

Control of fluid to and from the services and the feed and return passages 4, 5 is obtained by operation of a hand operated valve V for the props and a hand operated valve V1 for the cylinder and ram, and for this purpose the feed and return passages 4, 5 communicate with further passages leading to the valves, V, V1 in a manner to be particularly described with reference to FIGURE 2. Briefly the feed passage 4 communicates with a feed passage 4a leading to the valve V, the return passage 5 communicates with a return passage 5a leading to a return passage 5b, the service passages 7, 8, 9 communicate with a service passage 6 leading to a service passage 28a and the service passage 19 leads to a service passage 19a;

the passages 512, 28a and 19a open to the valve V which is of suitable known type to be operable for alternatively connecting the service passages 28a, 19a either to the feed passage 4a or to the return passage 55. Similarly the feed passage 4a leads to the valve V1, return passage 5a leads to a return passage 5c, and the service passages P, P1 lead to service Pa, Pla; the passages 5c, Pa: and Flu open to the valve V1 which is of suitable known type to be operable for alternatively connecting each of the services Pa, Pla in turn either to the feed passage 4a or to the return passage 50.

A number of ball valves and a relief valve are also incorporated and will be hereinafter particularly described with reference to FIGURE 4.

The valve controlled passages 51), 28a and 19a, for control of the props are grouped together as indicated in FIGURE 1 at a left hand location of the valve V, and the like passages 5c, Pa and Pla for control of the cylinder and ram, are grouped together at a right hand location of the valve V1.

The valves V, V1 are set in a block 10, FIGURE 2, and this is removably fitted to the valve 1 by Allen screws A, A1, A2 which extend freely through the block 10 and a part 111 of the valve 1 and screw into a rear part In of the valve 1, and Allen screws A3, A4, A5 which extend freely through the block 1c and screw into the part 1b.

Referring to FIGURE 4, this shows diagrammatically 4 the arrangement of passages and valves for control of the props, the remaining passages specifically for control of the cylinder and ram being omitted for clarity and because they have no particular significance in relation to the invention.

With the props in the extended roof supporting condition shown, the valve V is in a set position in which it connects feed passage 4a to the service passage 28a, and service passage 19 to the return passage 5b as indicated at X, X1. Pressure fluid thereby passes via line X through the service passage 6 and through non-return valves 49, 50, 51, in the service passages 7, 8, 9, so as to pass via the pipelines 10, 11, 12 to the lower cylinder ends of the props 13, 14, 15, fluid from the annuli of the props passing, via the pipelines 20, 21, passage 19, and line X1, to the return passage 5b. The pressure will be normally held on by the non-return valves 49, 50, 51 but when overload occurs the increased pressure through nonreturn valves 52, 53, 54 will open a relief valve 23 which is connected to the return line.

When it is required to contract the props, the valve V is turned to a release position in which the feed passage 4a is connected to the service passage 19, as indicated at Y, by which the pressure fluid passes to the annuli of the props and also pushes a valve member 18 to move a valve ball 16 off its seat, so that fluid from the lower cylinder ends of the props 13, 14, 15 can then pass freely, via the non-return valves 52, 53, 54, a passage 22, and a valve chamber 17, to the return passage 5b.

A valve such as the valve 1 is usually provided one on each support since it is suitable only for the control of one support.

The means hereinafter to be described are for enabling such modification to the valve 1 that it can be used for sequential control of a batch of props alternatively by (1) remote control of the batch of supports to operate in succession using a fluid pilot line, (2) pilot fluid or manual valve control of the next adjacent props for operation in any desired sequence, or (3) batch control using electric signals for successive or other desired sequential operation.

For each of these three alternatives the valve block 10 incorporating the valves V, V1 is removed from the valve -1 by removal of the screws A to A5, thus leaving the block part 1b with an exposed front face into which opens the groups of service and return passages 5b, 28a, 19a and 50, Pa and Flu, the feed passage 4a, and the holes B to B5 for the screws A to A5. The service passages 19, P, P1 are disconnected from their services and are plugged.

There is provided a remote control block 2, FIGURES 6, 7, which is formed with screw holes similar to those of the hand valve block 10, and this block 2 is fitted by screws C to C5, FIGURE 7, which are similar to but longer than, the screws A to A5. The block 2 has rear open service passages 55, 27, 28, FIGURE 6, and a feed passage 26, which register with the service passages 19a, 5b, 28a and feed passage 4a in the block part 1b. The remaining passages that were open in the block part 1b are covered over by blank parts of the block 2.

Mounted in the block 2 is a slide valve indicated generally at 29, FIGURE 7, which has a large diameter valve head 30 flanked by parallel valve surfaces 31, 32 and small and large pistons 33, 34 between which there is a stop 35. There ars also various inter-connecting passages to be hereinafter referred to. The parts are in the set position of the support, i.e. wherein the props 13, 14, 15 are vertically extended into roof supporting position. Fluid pressure entering the control valve block 1 into the feed passage 4a, FIGURE 8, is fed via passages 26 and 45 in the remote control block 2 to a chamber 46 at one end of the slide valve 29, also to a chamber 47 at the location of an annular neck 29a of the slide valve 29, and also to a chamber 48 at the other end of the slide valve 29. Fluid pressure acting in the chambers 46 and 48 hold the sections 2% and 290 of the slide valve 29 in the closed together position shown whereby fluid pressure can pass from the chamber 48 via the passage 28 to the service passage 6 and through non-return valves 49, 50, 51 in the service passages 7, 8 and 9 so as to pass via the lines 10, 11, 12 to the lower cylinder ends of the props 13, 14, 15 as before described. It will be noted that with the slide valve 29 in the closed together position shown, the annulus of the cylinder of each of the props and the annulus of the advancing cylinder and ram are open to the return line 5, via line 20, a passage 55, a chamber 56 associated with the slide valve 29, and the passage 27 connected to the return passage 5b. It will also be noted that a chamber 57 associated with the small piston 33 and a chamber 58 associated with the large piston 34 are constantly exhausted via a passage 59, the chamber 56, and the passage 55 connected to the return passage 5.

To operate the slide valve and consequently control the props, there may be fitted t0 the remote control block 2 any one of three alternative control blocks: (1) for batch control by a fluid pilot line, (2) next adjacent prop control, and (3) batch control by electric signals.

For this purpose the remote control block 2 has a feed passage 60 from the chamber 48, a passage 65 from the stop 35, which is hollow, a hole 71 from the feed passage 28, and four screw holes D to D3, FIGURE 6, all opening into the front face of the block; and a batch control block, a small hand operated valve block, and a solenoid valve block each have some complementary holes to be capable of being removably fitted to the remote control block 2 as and when required.

In the instance of the batch control block 3, FIG- URES 9 to 16, it has holes 60, 65, 71 to match the holes 60, 65, 71 and holes for screws E to E3 to screw through the block 3 into the screw holes D-D3 in the block 2.

The batch control block 3 also incorporates a slide valve indicated generally at 36, FIGURE 10, which has a large diameter valve head 37 flanked by parallel valve surfaces 38, 39, and a piston 40, with various inter-connecting passages to be hereinafter described with reference to FIGURE 13 and including a passage 41 in that figure for connection to adjacent supports to receive pilot signals, and passages 42, 43 connected to the annulus and cylinder of the advancing ram and cylinder 24, 25 and a passage 44 for conducting a pilot "signal to the next support, all in a manner to be hereinafter referred to.

With the working arrangement for the parts of the blocks 1 and 2 being as hereinbefore described, constant fluid pressure in the chamber 48, FIGURE 13, is fed via a passage 60 to a chamber 61 (see also FIGURE 11 for 60, 61) at one end of the slide valve 36 in the batch control block 3, thereby holding this slide valve 36 with its head 37 engaging a valve seating 62 instead of a valve seating 63, so that a passage 64 (see also FIGURE 11) is open to the passage 65 via a chamber 66.

When it is required for the props to be contracted and the support to be advanced by the advancing cylinder and ram, a pilot signal will be received either from a remote source or from an adjacent support at an appropriate end of the passage 41 in the batch control block 3. This pilot signal of fluid pressure passes via passage 64, the chamber 66, and the passage 65, to the hollow stop 35, such that the pressure is applied against the pistons 33 and 34 to move them outwards thereby to move the slide valve sections 29b and 29c outwards to the positions shown in FIGURE 14. This causes the slide valve section 29:: to close on a seating 67 thereby to isolate the passage 28 from the chamber 48. Pressure will be maintained in the chamber 48, but the same pressure acting on the large diameter piston 34 will hold it in the position shown. Similarly, pressure acting on the small diameter piston 33 will push the slide valve section 291) to push its head 30 off one seating 68 on to another seating 69 thereby isolating the passage 55 from the passage 27 and opening fluid pressure from the passage 45 via the chamber 47 to the passage 55 which will admit fluid to each annulus of the prop cylinder and to the annulus of the advancing cylinder and ram via the pipe 20', FIGURE 13. At the same time, pressure at the passage 55 will pass via the passage 19 to a chamber 70 and will act on the valve member 18 of the release valve to push the release valve ball 16 off its seat (FIGURE 14) so that fluid from the cylinders 13, 14, 15, FIGURE 13, of the props can then pass freely to the return line via the non-return valves 52, 53 and 54, the passage 22, and the chamber 17, to the return passage 5b.

Thus, pressure in the lower cylinder ends of the props 13, 14, 15 falls, and it also falls in the service line 6, in a line 71 therefrom (see also FIGURES 11, 12) and in a chamber 72 connected to the line 71, so that a spring 73 pushes a slide valve section 36a, FIGURE 5, of slide valve 36 against a seating 74 thereby to isolate a passage 75 (see also FIGURE 11) from the pilot outgoing signal passage 44.

Referring back to the pilot input signal, this passes not only into the passage 41, FIGURE 13, and also via passage 64 to passage 65, but also via passage 64 to the passage 43 from which it passes by flexible pipe 76 to a passage 77 in the end of the advancing cylinder 24. Presssure will be held in a chamber 78 due to a spring 79 pushing a differential slide valve member 80 against a seating 81.

During this time the props are slowly contracting and the support is being pulled up to the conveyor by contraction of the advancing cylinder and ram. When this contraction is completed piston 25a of the ram 25 will contact the small diameter of the slide valve member 80 and will push it off its seating 81 thereby opening passage 77 to a passage 82. The fluid pressure, now acting on the larger diameter part of the slide valve member 80 will overcome the spring 79 thereby holding the slide valve member 80 open until the pilot pressure is exhausted. In the meantime fluid will flow from the passage 82 along a flexible pipe 83 to the passage 42 in the batch control block 3. The fluid pressure, acting in a chamber 84 will push piston 40 (of a section 36b of the slide valve 36) to the right whereby this piston 40 pushes a section 360 of the slide valve 36 to the right so that the head 37 transfers from the seating 62 to the seating 63 as indicated in FIGURE 15.

Thus the pilot supply on the passage 64 is isolated from the passage 65. Therefore pressure in the hollow stop 35, FIGURE 13, will dissipate to the return line via two bleed holes 85, 86 in the pistons 33, 34 respectively. Consequently constant pressure, acting in chambers 46 and 48 will push the slide valve sections 29b, 290 back to their orignial positions, thereby re-opening the feed passage 4a to the lower cylinder ends of the props 13, 14, 15 and reopening the return passage 5b to the annulus of each prop cylinder as originally so that the props are re-extended towards the roof. When the slide valve section 360 was pushed to the right, FIGURE 15, this opened the passage 64 to the passage 75 whereby pressure is admitted to a chamber 87 associated with the slide valve section 3611. The spring 73 will keep the slide valve section 36a closed on the seating 74 during the time that the props are extending to the roof.

When the props have been thereby reset to the roof, pressure will build up in the passage 6, and this pressure, acting via the passage 71 and the chamber 72, FIGURE 13, will push the slide valve section 36a off the seating 74 as shown in FIGURE 16 against the action of the spring 73 thereby opening the chamber 87 to the pilot signal passage 44, thus passing a hydraulic signal to the next support to operate this with a similar sequence.

As previously intimated, at any time required, the batch control block 3 can be removed from the remote control block 2 by unscrewing the screws E to E3, FIG- URE 9, and there can be mounted on the remote control block 2 by the screws E to E3 a small disc valve block 88, FIGURE 17. As shown in FIGURE 19, the block 88 houses a small disc valve 93 which by a handle 94 controls a signal from an intermediate support, between two other supports, to pass either to a passage 95 connected to an adjacent support or to a passage 96 connected to another adjacent support. Thus, and assuming that the adjacent supports are set to the roof, if the control handle 94, FIGURE 17, is moved to the left the left hand support will release from the roof, and advance to the conveyor, and when the handle is moved back to neutral this left hand support will reset to the roof. Similarly if the control handle 94 is moved to the right the right hand support will release from the roof and advance to the conveyor, and when the handle is moved back to neutral this right hand support will reset to the roof.

Also as shown in FIGURE 18, the block 88 has a pilot passage 89 and this passage 89 is connected by a passage 90 to the hollow stop 35 so that a pilot signal passing, by actions of a similar handle to 94 on an adjacent support, to a ball valve 91 will act on the pistons 33, 34 to instigate release and advance, and resetting of the intermediate support as hereinbefore described for the adjacent support; alternatively a signal from the other adjacent support can be received in the passage 89 via a ball valve 92 for similar operations of the intermediate support.

As also intimated the batch control block 3, orfthe small disc valve block 88, can be replaced by a solenoid operated valve 97, FIGURES 20 to 22, this solenoid valve being mounted by the same screws E to E3 and four additional screws F-F3 on the front of the remote control block 2 and being of any known construction suitably having a signal passage for connection to the passage 90', FIGURE 18, so that the support can be operated by solenoid controlled operation of the control valve, using an electric signal from a remote position, say at the end of a row of supports, or from an adjacent support.

What I claim is:

1. Control valve means comprising a basic control valve block formed with throughway main fluid feed, return, and at least two service passages, and incorporating non-return valve means, a remote control valve block attached to the basic control valve block, and said remote control block having, main fluid feed, return, and at least two service passages which register with those of the basic valve block, and signal controllable valve means comprising, a slide valve in two separate co-axial sections whereof one of said valve sections is of unitary form operable for opening and closing communication between the feed passage and one of the service passages, and the other section is of two-way valve form for controlling communication between the feed passage and the other service passage and between the two service passages and the return passage.

2. Control valve means as claimed in claim 1 wherein said remote control valve block has signal and service passages extending from said signal controllable valve means to an outer surface of the block, and a third valve block is attached to the remote control valve block and has at least one passage registering with a passage in the remote control valve block.

3. Control valve means as claimed in claim 2 wherein said remote control valve block is fitted to said basic valve block, and said third block is fitted to said remote control block, in readily removable manner by screws.

4. Control valve means as claimed in claim 1 having the service passages adapted for connection to hydraulic mine roof supports and an advancing cylinder and ram.

5. Control valve means comprising a basic control valve block formed with throughway main fluid feed and return passages and at least first and second service passages, and incorporating non-return valve means; a remote control valve block attached to the basic control valve block and having, continuation feed, return, and

8 service passages which register with those of the basic valve block, signal controllable valve means comprising a slide valve in two separate co-axial sections and operable for selectively opening said first and second service passages to said feed and return passages, and signal and further continuation service passages extending from said signal controllable valve means to an outer surface of the block; and a third valve block attached to said remote control valve block and having at least a continuation signal passage registering with said signal passage, and a control valve device adapted for the control of signals through said continuation signal passage.

6. Control valve means as claimed in claim 5 wherein said third valve block has an extension service passage registering with a said further continuation service passage and leading to said control valve device, spring means biasing said control valve device, fluid passages associated with said control valve device for connection to a remote valve under control of one of the services, and input and output pilot fluid passages associated with said control valve device, whereby operation of one of the services can be instigated by an input pilot signal, operation of another of the services can be instigated by operation of said one of the services, and an output signal can be produced for passing on to an adjacent similar control valve means.

7. Control valve means as claimed in claim 5 wherein said third valve block has two separate output pilot signal passages, a manually operable two-way valve adapted for directing signals from the control valve means at one time to one of said output pilot signal passages and at another time to the other of said output pilot signal passages, whereby pilot signals can be passed from the control valve means to two adjacent similar control valve means at different times respectively.

8. Control valve means as claimed in claim 7 wherein said third valve block has two input pilot signal passages connected to said signal passage, whereby signals can be passed to the control valve means from two adjacent similar control valve means at diiferent times respectively.

9. Control valve means as claimed in claim 5 wherein said third valve block is of solenoid operated control valve, whereby signals can be passed to a batch of similar control valve means from a remote location electrically.

10. Control valve means comprising a first valve block, a second valve block secured to said first valve block, a plurality of third valve blocks inter-changeably connectable to said second valve block, said first valve block having main fluid feed and return passages and a plurality of service passages for connection to hydraulic props of a hydraulic roof support, and non-return control valves, said second valve block having main fluid feed return and service passages communicating with those of said first valve block and having an additional service passage for connection to said hydraulic props and to an advancing cylinder and ram therefor, and a two-part slide valve, controllable by fluid signals to control said props and cylinder and ram, and signal and service passages extending from said second valve block to an outer surface of the block, and said third valve block having at least a signal passage for registering with a signal passage of said second valve block, and a control valve device adapted for the control of signals through said signal passages, whereby a plurality of said props and cylinders and rams in a batch of roof supports are controllable to operate in predetermined sequential manner.

References Cited UNITED STATES PATENTS 3,068,898 12/ 1962 Meddock 137-59614- 3,215,l58 11/1965 Bass et al. l37269 WALTER A. SCHEEL, Primary Examiner R. I. SMITH, Assistant Examiner 

